/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package serv;

import entity.Perfil;
import java.io.IOException;
import java.util.Collection;
import javax.annotation.Resource;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceUnit;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.transaction.UserTransaction;

/**
 *
 * @author bruno
 */
public class ListaPerfis extends HttpServlet {
   
    @PersistenceUnit
    //The emf corresponding to
    private EntityManagerFactory emf;

    @Resource
    private UserTransaction utx;

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException {
        assert emf != null;  //Make sure injection went through correctly.
        EntityManager em = null;

        try {
            //begin a transaction
            utx.begin();
            //create an em.
            //Since the em is created inside a transaction, it is associsated with
            //the transaction
            em = emf.createEntityManager();

            //query for all the perfis in database
            Collection<Perfil> perfis = em.createQuery("select p from Perfil p").getResultList();

            //commit transaction which will trigger the em to
            //commit newly created entity into database
            utx.commit();

            request.setAttribute("perfis", perfis);

            //Forward to the jsp page for rendering
            request.getRequestDispatcher("ConsultaPerfis.jsp").forward(request, response);

        } catch (Exception ex) {
            throw new ServletException(ex);
        } finally {
            //close the em to release any resources held up by the persistebce provider
            if(em != null) {
                em.close();
            }
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    } 

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}
